docs: def tzinfo_eq(tzinfo1, tzinfo2, startYear = 2000, endYear=2020):
      """
      Compare offsets and DST transitions from startYear to endYear.
      """
      if tzinfo1 == tzinfo2:
          return True
      elif tzinfo1 is None or tzinfo2 is None:
          return False
  
      def dt_test(dt):
          if dt is None:
              return True
          return tzinfo1.utcoffset(dt) == tzinfo2.utcoffset(dt)
  
      if not dt_test(datetime.datetime(startYear, 1, 1)):
          return False
      for year in range(startYear, endYear):
          for transitionTo in 'daylight', 'standard':
              t1=getTransition(transitionTo, year, tzinfo1)
              t2=getTransition(transitionTo, year, tzinfo2)
              if t1 != t2 or not dt_test(t1):
                  return False
      return True